Speed Signal Circuit

AUDIO / VISUAL: AUDIO AND VISUAL SYSTEM: Speed Signal Circuit

Speed Signal Circuit

DESCRIPTION

The stereo component amplifier's Auto Sound Levelizer (ASL) adjusts the audio volume in accordance with vehicle noise. For example, when vehicle noise increases, the ASL automatically increases the audio's volume.
In a standard system, the ASL uses speed signals from the combination meter and a microphone to determine audio volume.
In a Mark Levinson system, the ASL uses speed signals from the combination meter to determine audio volume.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK WIRE HARNESS (STEREO COMPONENT AMPLIFIER - COMBINATION METER)




(a) Disconnect the S23 amplifier connector.
(b) Disconnect the C8 meter connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
2. CHECK COMBINATION METER ASSEMBLY (+S VOLTAGE)




(a) Jack up either of the rear wheels.
(b) Move the shift lever to N.
(c) Measure the voltage of the meter connectors.
Standard voltage:






NG -- GO TO METER / GAUGE SYSTEM
NG -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE